Stereopticon slide



June 14, 1938. D W 2,120,673

STEREOPTICON SLIDE Filed Sept. 29, 1936 ATTORNEY.

Patented June 14, 1938 owirso STATES reset-n Hnworth. N.

mpiioutlon fiemtemhtr fit, ittt, @erinl No. ittfi 3 errant (fill. tt tt) This invention reietes to improvements in slides or mats for use in stereonticon mochines.

otereopticou slides snot mete hove recently come into extensive use es on old in instructing children to drew one write. In one cues. for est-- ena le, the slide is e. smell piste oi frosted or srounci glass. The chilu writes or olrows on the irmted or grounrl suriece snot the result oi the childs efiorts is projected on e screen through the m instrumentelity oi e. stereopticon machine. An interest is creoteu one. ruuinteineol in the chilcl by the knowledge thrit his work will be displeyeol in resiistic end niezrniiiecl term on the screen beiore his olessmetes. The teeche'r msy with ism, cility end tor the benefit oi the entire close, point out existing, errors, mistakes or other ieulty execution or require members oi the clues to do so. The ohilri is thin tnurzht to remedy his rnistsires snot to be nest one! cureiui in the execution of so his worls to miticete or minimize criticism.

The chilcl should! be permitted to allow his mind to be centereci on the execution of his worlr snti not to be olevisteci into other chennels, such us, nienipuletion or requirement of careful lien- E5 tiling, of the slide, or determination us to the urea! limits within which the work is to be executed. "therefore, the slide or met, should be very simple in construction, light but oi sumcient body to melee it seli-sustuining, end. non-fragile, onol m should be provided with inteurni means for detininu the area. or field to be protected so thnt the child, without giving much thought to the matter will confine his writinu or olruwlng within that elven ores.

m From on economical stunclpoint, such sliole should be reusebie. Since such e slide is ireuuentiy used i'or treciuu purposes it shoulci be of such cherecter thet the stroller; oi the object to be tr ceol clue to the sliole should be reduced to e prior art discloses, in eciolition to ground or frosted glass plate, mets mode of very thin tronsperent ceilulosic materiel having a. body which is not seii sustsinine. This type is particularly used 45 ior preparing titles, diagrams, maps, etc., for i1- lustrsted lectures. These mots not being selfsusteinins have to be supported between two clear glass pistes. This preparstion consumes time, and the whole is dangerous by reason of possible 59 breeksee sud requires careful handling to prevent injury to the operator; and, of course, undesirable for use by children. Furthermore, these mats luck stebility, cannot be reused for other subjects. On account of its unmatted surface it 55 is dijmcult to write or draw thereon.

it is on object oi the present invention to provicie u very precticel, emcient, economical and simple trenslucent plate which can be written or drown upon and be used es it slide or met for s stereobticon. 7

it is s turther obiect oi this invention to proviole n sterecbticon slicie or met in the form of o. substantially thin, but self-sustaining, flexible; non-fragile piste bovine n matted surface adapted to receive murlsinss and impressions, and on in- 10 teursl opecgue msrrinel frame orvmoslr defining s fielu or ores. upon wmch the merkinrs and impressions may be muole, and which may be further chorecterizerl by bovine signal or visual indicating means on n. side eriue for guiding and adjusting the 1s siiole relntive to the stereopticon.

The shove one iurther objects, advantages and purposes will be'unilerstoou from a consideration oi the following detailed olescription, taken in connection with the accompanying drawing iormins pert oi this specification, with the further understanding that while the drawing shows o. precticel form of the invention, the latter is not confined to any strict conformity with the showing oi the drawing, but may be changed and; modified so long as such changes and modifications come within the scope of the appended claims.

In the drawing:

Fig. 1 is a. plen View oi s. sliole with its mutteol suriece uppermost and bearing a. drawn illustrnm tion.

Fig. 2 is it plain View of the slide blank with its obverse side uppermost.

Fig. i is a. sectional view taken along line ii-3 of his. ii.

The crowing shows an example of slide emboclying the invention.

Sliole it is o. substantially thin but se1i-sustwining, non-irseile, flernble piste preferably mode oi e. materiel such us, for example, cellu- 4m lolol, pyroxylin, other others end others of cellulose, or horn-lite mnteriels having approximately the physical properties of cellulosic materials. Cellulose acetate forms s. suitable substance for the slide blank. 5

The slide ii is provirieci with e mattecl or dulleround like surface B cspeble of receiving and retaining marks, designs, drawings or other markings, impressions and characters made with pencil, crayon, ink, water color, or the like; but which 50 surface may be substsntielly cleared of such char-- acters by suitable means, such as, for instance, a. damp cloth or sponge. By means of its flexibility the slide may be inserted in a. typewriter.

Slide it is preferably made of s. thickness that 5 will not cause appreciable parallax of the object to be traced, if so desired.

Preferably provided on the matted or dull surface B of the plate It! is an opaque marginal frame, border or mask II. This frame or mask II is made integral with the slide material as by being printed or stencilled thereon, and serves a two-fold purpose, namely, to define the field or area I! upon which the work may be executed so that the same may be wholly exposed for projection upon the screen, and to permit the work to stand out by contrast therewith upon the screen.

Upon a margin or side IQ of the slide there may be carried indicia or characters, such as, for example, at one end, a star, an arrow with its head pointed in the direction of the star and adjacent the arrow, the word Thumb", generally indicated by the numeral l3; and at the other end an arrow pointed in the opposite direction to the previously mentioned arrow and adjacent this latter .arrow the word "Top, generally indicated by the numeral It. Any other signal or visual indicating means may be employed.

When the slide is inserted in the stereoptican machine, the polished or unmatted side indicated in Fig. 2 by the letter A will be toward the screen and the dull and matted side B carrying the drawing or other character l5 will be toward the light source of the machine.

In order to assure proper insertion of the slide in the machine, the characters or indicia I3 are arranged at the bottom of edge l6, and the characters or indicia M at the top thereof. The slide is gripped at the bottom of edge l6 between the thumb and forefinger of the hand for insertion into the machine.

The edge l6 may be provided with other characters, as for example, the trade-mark "Slidecraft indicated by the numeral ll; or the same may be provided with instructions as to the use of the slide. Although the characters or indicia are shown as being opaque against a translucent or transparent background, any other suitable arrangement may be employed, as by way of example, transparent characters or indicia against an opaque background. The picture l5 can be prepared in pencil, ink, crayon, water color, or the like, and can easily be removed by washing, leaving the slide clear and clean for repeat use.

While I have here shown what I believe to be a simple and efficient form' of the invention it is through the exigencies of use may be resorted to without transcending the scope of the invention as defined by the appended claims.

Having described my invention what I claim as new and desire to secure by Letters Patent, is:--

1. As an article of manufacture, a one-piece single sheet stereopticon slide comprising a selfsustaining non-fragile, flexible plate of substantially transparent material which is roughened on one side to render it substantially translucent and to receive markings thereon, and an opaque marginal frame on the sheet and applied integral therewith defining a field or area on the roughened sheet within which markings may be applied by a marking device to said roughened surface and to cause said markings to stand out in contrast with the frame when projected on a screen.

2. As an article of manufacture, a one-piece single sheet stereopticon slide comprising a selfsustaining, non-fragile flexible plate of substantially transparent material having the physical properties of cellulosic material which plate is roughened on one side to renderit substantially translucent and to receive removable markings thereon, and an opaque marginal frame printed on the sheet defining a field or area on the roughened sheet within which markings may be applied by a marking device to said roughened surface and to cause said markings to stand out in contrast with the frame when projected on a screen.

3. As an article of manufacture, a one-piece single sheet stereopticon slide comprising a selfsustaining, non-fragile flexible plate of substantially transparent material having the physical properties of cellulosic material which plate is roughened on one side to render it substantially translucent and to receive removable markings thereon, an opaque marginal frame printed on the sheet defining a field or area on the roughened sheet within which markings may be applied by a marking device to said roughened surface and to cause said markings to stand out in contrast with the frame when projected on a screen, and a marginal border along at least one edge of said sheet with indicia thereon to indicate 0 positioning of the plate for insertion into a 5 stereopticon.

PAUL M. MEADOWS. 

